Debian Administration Training Course

Debian Distribution

Understanding Debian

• Selecting the appropriate Debian version
• Accessing Debian support and resources
• The Debian community ecosystem

Console Fundamentals

• Understanding the shell prompt
• Using the shell prompt within an X environment
• Managing the root account and using root privileges (su, sudo, executing programs as root under X)
• Utilizing GUI-based system administration tools
• Working with virtual consoles
• Exiting the command prompt correctly
• Properly shutting down the system
• Restoring a stable console state
• Recommended additional packages for beginners
• Creating additional user accounts
• Configuring sudo access

The Filesystem

• Managing filesystem permissions
• Controlling default permissions for new files using umask
• Setting permissions for user groups
• Understanding timestamps
• Working with symbolic and hard links
• Using named pipes (FIFOs)
• Understanding sockets
• Handling device files
• Special device file operations
• Interacting with procfs and sysfs

Midnight Commander (MC)

• Customizing the MC interface
• Launching Midnight Commander
• Using the file manager within MC
• Employing command-line shortcuts in MC
• Using the built-in editor in MC
• Using the built-in viewer in MC
• Configuring auto-start features in MC
• Using the FTP virtual filesystem in MC

Essential Unix-like Work Environment

• Understanding the login shell
• Customizing bash settings
• Using special keyboard strokes
• Navigating with the pager
• Setting a default text editor
• Exiting vim correctly
• Logging shell activities
• Essential Unix commands

Basic Shell Command Usage

• Executing commands and using environment variables
• Understanding the "$LANG" variable
• Understanding the "$PATH" variable
• Understanding the "$HOME" variable
• Using command-line options
• Utilizing shell glob patterns
• Checking command return values
• Constructing command sequences and using shell redirection
• Creating command aliases

Unix-like Text Processing

• Standard Unix text tools
• Using regular expressions
• Applying replacement expressions
• Performing global substitutions with regular expressions
• Extracting data from text-based tables
• Script snippets for piping commands

Debian Package Management

Prerequisites for Debian Package Management

• Configuring packages
• Basic safety precautions
• Managing systems with continuous upgrades
• Fundamentals of Debian archives
• Understanding package dependencies
• The workflow of package management events
• Initial steps when encountering package management issues

Core Package Management Operations

• Comparing apt-get/apt-cache with aptitude
• Performing basic package management via the command line
• Using aptitude interactively
• Applicable key bindings for aptitude
• Package views available in aptitude
• Search options in aptitude
• Using regex formulas in aptitude
• Resolving dependencies with aptitude
• Reviewing package activity logs

Practical Aptitude Examples

• Listing packages using regex matching on names
• Browsing packages with regex matching
• Permanently purging removed packages
• Organizing auto/manual installation status
• Performing system-wide upgrades

Advanced Package Management Operations

• Advanced command-line package management techniques
• Verifying installed package files
• Implementing safeguards against package issues
• Searching package metadata

Internal Mechanics of Debian Package Management

• Archive metadata structure
• The top-level "Release" file and authenticity verification
• Archive-level "Release" files
• Fetching package metadata
• Package state tracking in APT
• Package state tracking in aptitude
• Local caching of fetched packages
• Naming conventions for Debian package files
• Using the dpkg command
• Using the update-alternative command
• Using the dpkg-statoverride command
• Using the dpkg-divert command

Recovering from a Broken System

• Addressing incompatibilities with legacy user configurations
• Handling file conflicts between different packages
• Repairing broken package scripts
• Using dpkg commands for rescue operations
• Restoring package selection data

Package Management Tips

• Strategies for selecting Debian packages
• Managing packages from mixed archive sources
• Adjusting candidate package versions
• Working with Updates and Backports
• Automating package downloads and upgrades
• Limiting APT download bandwidth
• Performing emergency package downgrades
• Identifying package uploaders
• Using the equivs package
• Porting packages to stable systems
• Configuring proxy servers for APT
• Managing small public package archives
• Recording and replicating system configurations
• Converting or installing non-Debian binary packages
• Extracting packages without using dpkg
• Further resources for package management

System Initialization

• Overview of the bootstrap process
• BIOS, boot loaders, and mini-Debian systems
• The concept of runlevels
• Configuring runlevels
• Examples of runlevel management
• Default parameters for init scripts
• Managing the hostname
• Filesystem configuration at boot
• Initializing network interfaces
• Starting network services
• Interpreting system messages
• Interpreting kernel messages
• The udev subsystem
• Initializing kernel modules

Authentication and Security

• Standard Unix authentication methods
• Managing account and password data
• Creating strong passwords
• Generating encrypted passwords
• Understanding PAM and NSS
• Configuring files accessed by PAM and NSS
• Modern centralized system management approaches
• Why GNU su does not support the wheel group
• Enforcing stricter password policies
• Implementing additional access controls
• Configuring sudo
• Using SELinux and AppArmor
• Restricting access to specific server services
• Securing the authentication process
• Transmitting passwords securely over the internet
• Using Secure Shell (SSH)
• Additional security measures for internet exposure
• Protecting the root password

Network Configuration

Basic Network Infrastructure

• Understanding domain names
• Hostname resolution processes
• Naming network interfaces
• LAN network address ranges
• Network device driver support

Modern Desktop Network Configuration

• Using GUI-based network configuration tools

Low-Level Network Configuration

• Using Iproute2 commands
• Performing safe low-level network operations

Network Optimization

• Determining the optimal MTU
• Setting the MTU
• Optimizing TCP over WAN links

Netfilter Infrastructure

Network Applications

Mail System

• Fundamentals of modern mail services
• Mail configuration strategy for workstations

Mail Transport Agent (MTA) and Mail User Agent (MUA)

• Overview of exim4
• Basic usage of Mutt (MUA)

Mail Delivery Agent (MDA) with Filtering

• Configuring maildrop
• Configuring procmail
• Redelivering contents from mbox files

POP3/IMAP4 Servers

Remote Access Servers and Utilities (SSH)

• Fundamentals of SSH
• Using port forwarding for SMTP/POP3 tunneling
• Connecting without using remote passwords
• Interoperating with non-standard SSH clients
• Setting up ssh-agent
• Shutting down a remote system via SSH
• Diagnosing SSH issues

Other Network Application Servers

Other Network Application Clients

Diagnosing System Daemons

The X Window System

• Setting up the desktop environment
• Understanding server/client relationships
• Configuring the X server
• Starting the X Window System
• Launching X sessions using gdm
• Customizing X sessions (traditional method)
• Customizing X sessions (modern method)
• Connecting remote X clients via SSH
• Securing X terminals over the internet
• Managing X applications
• Using X office suites
• Using X utility applications

System Tips

The Screen Program

• Use cases for screen(1)
• Key bindings for the screen command

Data Logging and Presentation

• Managing the log daemon
• Using log analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Colorizing shell output
• Colorizing command prompts
• Recording editor actions for complex repetitions
• Capturing graphic images of X applications
• Tracking changes in configuration files

Data Storage Tips

• Configuring disk partitions
• Accessing partitions using UUIDs
• Filesystem configuration
• Creating filesystems and checking integrity
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock settings
• Hard disk performance optimization
• Predicting hard disk failures using SMART
• Expanding storage space with LVM
• Expanding storage by mounting additional partitions
• Expanding storage using symbolic links
• Expanding storage using aufs

Data Encryption Tips

• Encrypting removable disks with dm-crypt/LUKS
• Encrypting swap partitions with dm-crypt
• Automatically encrypting files with eCryptfs
• Auto-mounting eCryptfs volumes

Monitoring, Controlling, and Initiating Program Activities

• Measuring process execution time
• Managing scheduling priority
• Using the ps command
• Using the top command
• Listing files opened by a specific process
• Tracing program activities
• Identifying processes using specific files or sockets
• Repeating commands at constant intervals
• Looping command execution over multiple files
• Launching programs from the GUI
• Customizing programs to be started automatically
• Terminating processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System Maintenance Tips

• Identifying logged-in users
• Sending system-wide warnings
• Identifying hardware components
• Configuring hardware
• Synchronizing system and hardware time
• Terminal configuration
• Sound infrastructure setup
• Disabling screen savers
• Disabling beep sounds
• Monitoring memory usage
• Performing system security and integrity checks

The Kernel

• Managing kernel parameters
• Using kernel headers
• Compiling the kernel and related modules
• Compiling kernel source: Debian standard method
• Compiling module source: Debian standard method
• Managing non-free hardware drivers

Virtualized Systems

• Virtualization tool suites
• Virtualization workflows
• Mounting virtual disk image files
• Using chroot systems
• Managing multiple desktop systems

Data Management

Sharing, Copying, and Archiving

• Archive and compression utilities
• Copy and synchronization tools
• Common idioms for archiving
• Common idioms for copying
• Common idioms for file selection
• Backup and recovery strategies
• Backup utility suites
• Example system backup script
• Data backup copy script
• Handling removable storage devices
• Sharing data over the network
• Managing archive media

Binary Data Handling

• Viewing and editing binary data
• Manipulating files without mounting disks
• Data redundancy techniques
• Data file recovery and forensic analysis
• Splitting large files into smaller segments
• Clearing file contents securely
• Working with dummy files
• Wiping an entire hard disk
• Erasing unused areas of a hard disk
• Undeleting deleted but still open files
• Finding all hard links
• Investigating invisible disk space consumption

Data Security Infrastructure

• GnuPG key management for signing and encryption
• Using MD5 checksums